The application proposes to examine the domain of Perception as applied to young infants. P50 sensory gating will be utilized as the primary measure of Perception. Three approaches will be utilized: (1) Examine if infant P50 sensory gating is predictive of 4 year-old behavior; (2) Examine if infant P50 sensory gating is related to 4 year-old measures of Perception, Attention, and Cognitive Control; and (3) Identify the neural correlates of infant P50 sensory gating utilizing fMRI. This work should help to clarify the validiy of the RDoC classification system in young infants.